One of the many ways of representing a tree is to have an array(of length same as number of nodes), where each element in the node denotes the parent of that node.
Please note –
* An element with parent = -1 is the root element.
* An element with the least index becomes the left most child. (ie. a node with always be on left of all its siblings that have higher index than it)
* When printing a level of tree you need to maintain left to right order.
Eg –
{-1, 0, 0, 1, 1} would represent a tree with –
* 0 as root
* 1 and 2 as children of 0
* 3 and 4 as children of 1

Given a similar representation, you have to print reverse level order traversal of the corresponding tree.
Level order traversal of a tree is where we traverse levels of tree one by one.

Eg –
For the above given tree, level order traversal would be –
0
1 2
3 4
And hence, the reverse level order traversal is –
3 4
1 2
0